//
// Document.h
//
// Library: XML
// Package: DOM
// Module:  DOM
//
// Definition of the DOM Document class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef DOM_Document_INCLUDED
#define DOM_Document_INCLUDED


#include "Poco/AutoReleasePool.h"
#include "Poco/DOM/AbstractContainerNode.h"
#include "Poco/DOM/DocumentEvent.h"
#include "Poco/DOM/Element.h"
#include "Poco/XML/NamePool.h"
#include "Poco/XML/XML.h"
#include "Poco/XML/XMLString.h"


namespace Poco
{
namespace XML
{


    class NamePool;
    class DocumentType;
    class DOMImplementation;
    class DocumentFragment;
    class Text;
    class Comment;
    class CDATASection;
    class ProcessingInstruction;
    class Attr;
    class EntityReference;
    class NodeList;
    class Entity;
    class Notation;


    class XML_API Document : public AbstractContainerNode, public DocumentEvent
    /// The Document interface represents the entire HTML or XML document. Conceptually,
    /// it is the root of the document tree, and provides the primary access to the
    /// document's data.
    ///
    /// Since elements, text nodes, comments, processing instructions, etc. cannot exist
    /// outside the context of a Document, the Document interface also contains the
    /// factory methods needed to create these objects. The Node objects created have a
    /// ownerDocument attribute which associates them with the Document within whose
    /// context they were created.
    {
    public:
        using AutoReleasePool = Poco::AutoReleasePool<DOMObject>;

        explicit Document(NamePool * pNamePool = 0);
        /// Creates a new document. If pNamePool == 0, the document
        /// creates its own name pool, otherwise it uses the given name pool.
        /// Sharing a name pool makes sense for documents containing instances
        /// of the same schema, thus reducing memory usage.

        explicit Document(unsigned long namePoolSize);
        /// Creates a new document using a name pool with the given size, which
        /// should be a prime number (e.g., 251, 509, 1021, 4093).

        Document(DocumentType * pDocumentType, NamePool * pNamePool = 0);
        /// Creates a new document. If pNamePool == 0, the document
        /// creates its own name pool, otherwise it uses the given name pool.
        /// Sharing a name pool makes sense for documents containing instances
        /// of the same schema, thus reducing memory usage.

        Document(DocumentType * pDocumentType, unsigned long namePoolSize);
        /// Creates a new document using a name pool with the given size, which
        /// should be a prime number (e.g., 251, 509, 1021, 4093).

        NamePool & namePool();
        /// Returns a pointer to the documents Name Pool.

        AutoReleasePool & autoReleasePool();
        /// Returns a pointer to the documents Auto Release Pool.

        void collectGarbage();
        /// Releases all objects in the Auto Release Pool.

        void suspendEvents();
        /// Suspends all events until resumeEvents() is called.

        void resumeEvents();
        /// Resumes all events suspended with suspendEvent();

        bool eventsSuspended() const;
        /// Returns true if events are suspended.

        bool events() const;
        /// Returns true if events are not suspended.

        const DocumentType * doctype() const;
        /// The Document Type Declaration (see DocumentType) associated with this document.
        /// For HTML documents as well as XML documents without a document type declaration
        /// this returns null. The DOM Level 1 does not support editing the Document
        /// Type Declaration. docType cannot be altered in any way, including through
        /// the use of methods inherited from the Node interface, such as insertNode
        /// or removeNode.

        const DOMImplementation & implementation() const;
        /// The DOMImplementation object that handles this document. A DOM application
        /// may use objects from multiple implementations.

        Element * documentElement() const;
        /// This is a convenience attribute that allows direct access to the child node
        /// that is the root element of the document. For HTML documents, this is the
        /// element with the tagName "HTML".

        Element * createElement(const XMLString & tagName) const;
        /// Creates an element of the type specified. Note that the instance returned
        /// implements the Element interface, so attributes can be specified directly
        /// on the returned object.
        ///
        /// In addition, if there are known attributes with default values, Attr nodes
        /// representing them are automatically created and attached to the element.

        DocumentFragment * createDocumentFragment() const;
        /// Creates an empty DocumentFragment object.

        Text * createTextNode(const XMLString & data) const;
        /// Creates a text node given the specified string.

        Comment * createComment(const XMLString & data) const;
        /// Creates a comment node given the specified string.

        CDATASection * createCDATASection(const XMLString & data) const;
        /// Creates a CDATASection node whose value is the specified string.

        ProcessingInstruction * createProcessingInstruction(const XMLString & target, const XMLString & data) const;
        /// Creates a ProcessingInstruction node given the specified target and data strings.

        Attr * createAttribute(const XMLString & name) const;
        /// Creates an Attr of the given name. Note that the Attr instance can then
        /// be set on an Element using the setAttributeNode method.

        EntityReference * createEntityReference(const XMLString & name) const;
        /// Creates an EntityReference object. In addition, if the referenced entity
        /// is known, the child list of the EntityReference node is made the same as
        /// that of the corresponding Entity node.

        NodeList * getElementsByTagName(const XMLString & name) const;
        /// Returns a NodeList of all Elements with a given tag name in the order
        /// in which they would be encountered in a preorder traversal of the
        /// document tree.
        ///
        /// The returned NodeList must be released with a call to release()
        /// when no longer needed.

        // DOM Level 2
        Node * importNode(Node * importedNode, bool deep);
        /// Imports a node from another document to this document. The returned node
        /// has no parent; (parentNode is null). The source node is not altered or removed
        /// from the original document; this method creates a new copy of the source
        /// node.
        /// For all nodes, importing a node creates a node object owned by the importing
        /// document, with attribute values identical to the source node's nodeName
        /// and nodeType, plus the attributes related to namespaces (prefix, localName,
        /// and namespaceURI). As in the cloneNode operation on a Node, the source node
        /// is not altered.
        /// Additional information is copied as appropriate to the nodeType, attempting
        /// to mirror the behavior expected if a fragment of XML or HTML source was
        /// copied from one document to another, recognizing that the two documents
        /// may have different DTDs in the XML case.

        Element * createElementNS(const XMLString & namespaceURI, const XMLString & qualifiedName) const;
        /// Creates an element of the given qualified name and namespace URI.

        Attr * createAttributeNS(const XMLString & namespaceURI, const XMLString & qualifiedName) const;
        /// Creates an attribute of the given qualified name and namespace URI.

        NodeList * getElementsByTagNameNS(const XMLString & namespaceURI, const XMLString & localName) const;
        /// Returns a NodeList of all the Elements with a given local name and
        /// namespace URI in the order in which they are encountered in a
        /// preorder traversal of the Document tree.

        Element * getElementById(const XMLString & elementId) const;
        /// Returns the Element whose ID is given by elementId. If no such
        /// element exists, returns null. Behavior is not defined if more
        /// than one element has this ID.
        ///
        /// Note: The DOM implementation must have information that says
        /// which attributes are of type ID. Attributes with the name "ID"
        /// are not of type ID unless so defined. Implementations that do
        /// not know whether attributes are of type ID or not are expected to
        /// return null. This implementation therefore returns null.
        ///
        /// See also the non-standard two argument variant of getElementById()
        /// and getElementByIdNS().

        // DocumentEvent
        Event * createEvent(const XMLString & eventType) const;

        // Node
        const XMLString & nodeName() const;
        unsigned short nodeType() const;

        // EventTarget
        bool dispatchEvent(Event * evt);

        // Extensions
        Entity *
        createEntity(const XMLString & name, const XMLString & publicId, const XMLString & systemId, const XMLString & notationName) const;
        /// Creates an Entity with the given name, publicId, systemId and notationName.
        ///
        /// This method is not part of the W3C Document Object Model.

        Notation * createNotation(const XMLString & name, const XMLString & publicId, const XMLString & systemId) const;
        /// Creates a Notation with the given name, publicId and systemId.
        ///
        /// This method is not part of the W3C Document Object Model.

        Element * getElementById(const XMLString & elementId, const XMLString & idAttribute) const;
        /// Returns the first Element whose ID attribute (given in idAttribute)
        /// has the given elementId. If no such element exists, returns null.
        ///
        /// This method is an extension to the W3C Document Object Model.

        Element *
        getElementByIdNS(const XMLString & elementId, const XMLString & idAttributeURI, const XMLString & idAttributeLocalName) const;
        /// Returns the first Element whose ID attribute (given in idAttributeURI and idAttributeLocalName)
        /// has the given elementId. If no such element exists, returns null.
        ///
        /// This method is an extension to the W3C Document Object Model.

    protected:
        ~Document();

        Node * copyNode(bool deep, Document * pOwnerDocument) const;

        DocumentType * getDoctype();
        void setDoctype(DocumentType * pDoctype);

    private:
        DocumentType * _pDocumentType;
        NamePool * _pNamePool;
        AutoReleasePool _autoReleasePool;
        int _eventSuspendLevel;

        static const XMLString NODE_NAME;

        friend class DOMBuilder;
    };


    //
    // inlines
    //
    inline NamePool & Document::namePool()
    {
        return *_pNamePool;
    }


    inline Document::AutoReleasePool & Document::autoReleasePool()
    {
        return _autoReleasePool;
    }


    inline const DocumentType * Document::doctype() const
    {
        return _pDocumentType;
    }


    inline DocumentType * Document::getDoctype()
    {
        return _pDocumentType;
    }


}
} // namespace Poco::XML


#endif // DOM_Document_INCLUDED
